Cassia Seed is the dried ripe seed of Cassia obtusifolia L. or Cassia tora L. (Fam. Leguminosae). The ripe legume is collected in autumn and dired in the sun, then the seed is tapped out and removed from foreign matter.
Description: Semen Cassiae Obtusifoliae Slightly rhomboidal-cuboid or shortly cylindrical, both ends pararell and oblique, 3-7 mm long, 2-4 mm wide. Externally greenish-brown or dark brown, smooth and lustrous. One end relatively even, the other end oblique and acuminate, dorsal and ventral surfaces exhibiting a raised rib respectively, with an obliquely symmetrical and paler-coloured dented line on each side of a rib. Texture hard and uneasily broken. Testa thin, cotyledons 2, yellow, S-shaped. Odour, slight; taste, slightly bitter.
Semen Cassiae Torae: Shortly cylindrical, relatively small, 3-5 mm long, 2-3 mm wide, with broad yellowish-brown bands on both sides of the rib.
Identification: (1) To 0.5 g of the powder add 20 ml of dilute sulfuric acid and 10 ml of chloroform, heat gently under reflux for 15 minutes. Allow to cool, transfer to a separator. Separate the chloroform layer and shake with 10 ml of sodium hydroxide TS, allow to stand; a red colour is produced in aqueous layer. If a brown colour is produced, add 1-2 drops of hydrogen peroxide TS to the separated aqueous layer and heat for 4 minutes in a water bath, a red colour is produced.
(2) Macerate 1 g of the powder with 10 ml of methanol for 1 hour, fliter, evaporate the filtrate to dryness, dissolve the residue with 10 ml of water, add 1 ml of hydrochloric acid, heat on a water bath for 30 minutes, cool immediately, extracted with two quantities, each of 20 ml, of ether, combined the test solution, evaporate to dryness, dissolve the residue with 1 ml of chloroform as the test solution. Dissolve emodin and chrysophanol CRS with ethanol to produce a solution containing each of 1 mg per ml as the reference solution. Carry out the method for thin layer chromatography (Appendix VI B), using silica gel H containing sodium carboxymethylcellulose as the coating substance and petroleum ether (30-60oC)-ethyl formate-formic acid (15: 5: 1) as the mobile phase. After developing and removal of the plate, dry it in air, examine under ultraviolet light (365 nm). The orange fluroscent spots in the chromatogram obtained with the test solution correspond in positon and colour to the spots in the chromatogram obtained with the reference solution. The spots turn to red on exposure to ammonia vapour.
Processing: Semen Cassiae Eliminate foreign matter, wash clean and dry. Break into pieces before use.
Semen Cassiae (stir-baked): Stir-bake the clean Semen Cassiae as described under the method for simple stir-baking (Appendix II D) until slightly scented. Break into pieces before use.
Action: To remove heat, to improve eyesight, and to relax bowels.
Indications: Inflammation of the eye with pain, photophobia and lacrimination; headache, dizziness, blurred vision and constipation.
Usage and dosage: 9-15 g.
Storage: Preserve in a dry place.